Heater



1957 v J. A. M DONALD 3,351,042

' HEATER Filed April 8, 1966 3 Sheets-Sheet 1 CONTRO SYSTEM INVENTOR V JOHN A.MAC DONALD 80 BY M),

ATTORNEY Nov. 7, 1967 Filed April 8 1966 J. A. M DONALD 3,351,042

HEATER 5 Sheets-Sheet 2 FIGZ I NVENTOR JOHN A MAC DONALD ATTORNEY J. A. MZCDONALD Nov. 7, 1967 HEATER 5 Sheets-Sheet 5 Filed April 8, 1966 INVENTOR J OHN A MAC DONALD BY My [0/ ATTORNEY United States Patent Quebec, Canada, as- Chicago, III., a corpora- This invention relates in general to a heater, and more particularly to a heater for use on in-transit or stationary railroad stock, such as insulated box cars, refrigerator cars, cabs or the like, for providing heat to the heating system of the railroad stock, although other uses and purposes may be apparent to one skilled in the art.

The heater of the present invention includes a double burner, wherein a main burner is cycled on and oif by a control responding to the heating system, while a pilot burner is at all times in operation to provide a low fire. The main burner serves to heat a heating media flowing through a heating coil, while the pilot burner serves to preheat or vaporize the main burner fuel and thereafter ignite same. The burners are arranged so that correct proportions of air are metered to the burners to insure sufficient combustion. Diesel type fuel oil or kerosene may be used as a fuel. Flow of the heating media through the heating system and heating coil of the heater is accomplished by the thermo siphoning principle which eliminates the need for any circulating pump. The unit is entirely self-contained and does not require any external power source.

It is, therefore, an object of the present invention to provide a new and improved heater for use in heating of a heating media.

Another object of this invention resides in the provision of a new and improved heater for use on in-transit or staitonary railroad stock including refrigerator cars, cabs, insulated box cars or the like.

A further object of this invention resides in the provision of a heater for use on railroad stock that is entirely self-contained and does not require any external power source.

A still further object of this invention is to provide a heater for use on railroad stock that includes a main burner and a pilot burner arranged therebelow for preheating or vaporizing the fuel in the main burner and igniting the fuel.

Another object of this invention is in the provision of a heater for use on railroad stock that includes a main burner in combination with the pilot burner, wherein the pilot burner is burning all of the time and the main burner cycles on and off depending upon the heat requirements of the heating system served by the heater.

Still another object of this invention resides in the provision of the heater including a main burner and a pilot burner arranged therebelow in combination with a plurality of combustion air chambers that are arranged to meter correct proportions of air to the firepots of the burners thereby insuring eificient combustion.

A still further object of this invention is in the provision of a heater for railroad stock that is ruggedly constructed, does not require any wicks for continuous operation, and is not in need of periodic replacement of parts and therefore has long life with minimum maintenance.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a vertical sectional view taken through the heater according to the present invention and also illustrating diagrammatically the fuel supply and control system;

FIG. 2 is a vertical sectional view taken substantially along line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view taken substantially along line 33 of FIG. 1;

FIG. 4 is a detailed sectional view taken substantially along line 44 of FIG. 3;

FIG. 5 is a transverse sectional 'view taken substantially along line 55 of FIG. 1; and

FIG. 6 is a transverse sectional view taken substantially along line 66 of FIG. 1.

Referring now to the drawings and particularly to FIGS. 1 and 2, the heater of the present invention includes generally a main burner 10, a. pilot burner 11 arranged below the main burner, and a heating coil 12 arranged above the main burner. The heating coil 10 iS adapted to have the heating media circulated therethrough and into a heating system of a railroad car such as an insulated box car, a refrigerator car, a cab or the like. More particularly, the heating coil 12 would most likely be connected to thin tubing mounted within a car, and circulated therethrough by the thermo siphoning principle which does not require any circulating pump. The heating media may be a mixture of anti-freeze and water or any other suitable material.

The main burner 10 includes an annular combustion chamber 13 and inner and outer annular combustion air chambers 14 and 15 arranged at the inner and outer sides of the combustion chamber 13. The combustion chamber 13 is defined by inner and outer concentric walls 16 and 17, and a bottom wall 18. The inner combustion air chamber 14 is defined by the inner concentric wall 16 and an inner combustion air chamber wall 19 that is concentric to the wall 16. The wall 19 extends all the way to the bottom wall 18, while the concentric wall 16 extends to a point slightly spaced upwardly from the bottom wall 18 and is joined to the wall 19 by an annular bottom wall 20. The upper end of the wall 16 is joined to the upper end of the wall 19 by an upper wall 21. A single row of openings or holes 22 is provided in the inner concentric wall 16 for introducing air from the combustion air chamber 14 into the combustion chamber 13. A tubular extension 23 is provided for each of the holes or openings 22 and extends inwardly .and slightly down- Wardly from the inner concentric wall 16. A flame supporting baffle 24 is mounted in the combustion chamber 13 and spaced from the inner concentric wall 16 in concentric relation therewith, and arranged so that the tubular extensions 22 cause the air from the combustion air chamber 14 to be discharged inwardly of the inner concentric wall 16 and at the upper inner area defined between the baflle 24 and the concentric wall 16.

The outer combustion air chamber 15 is defined by the outer concentric wall 17 and an outer combustion air chamber wall 25. The upper end of the combustion chamber 15 is closed by an upper Wall 26, while the lower end is opened. A plurality of vertically spaced rows of air holes or orifices 27a, 27b, 27c, 27d, 27a and 27 are provided in the outer concentric wall 17 to introduce air from the combustion air chamber 15 into the combustion chamber 13. Each row of holes or orifices includes a plurality of circumferentially arranged holes or orifices. A tubular extension 28 is provided in registry with the orifices 27a, while the tubular extension 29 is provided in registry with each of the orifices 27 1, wherein the tubular extensions extend inwardly from the outer concentric wall 17 and slightly downwardly to introduce the combustion air into the center of the combustion chamber. A choke 30 is provided at the upper end of the combustion chamber 13 and supported by the outer concentric wall 17 and extending inwardly therefrom.

Fuel is fed into the combustion chamber 13 of the main burner 10 through a plurality of fuel openings or orifices 31, FIGS. 1, 2 and 5. While four equally circumferentially spaced fuel openings 31 are shown, it should be appreciated that a greater or lesser number may be provided. However, the four openings are arranged so that if the heater is tilted slightly in one direction or the other, the fuel flow into the combustion chamber 13 will not be impeded. Fuel is delivered to the fuel openings through an annular fuel manifold 32 as connected to each of the fuel openings 31 by a connecting line 33. The fuel manifold 32 is in turn connected to a supply line 34.

The pilot burner 11, arranged below the main burner 10, includes an upstanding cylindrical wall 35 closed at the lower end by a bottom wall 36. The wall 35 is sized so that it is greater than the inner combustion air chamber wall 19 which also serves as a flue for the pilot burner, and so that the outer extremities of the pilot burner underlie the inner extremities of the main burner. The wall 35 and bottom wall 36 define a pilot combustion chamber 37. Fuel is fed to the combustion chamber 37 by a plurality of fuel openings or orifices 38 arranged in the bottom wall 36 of the combustion chamber, and shown particularly in FIGS. 1, 2 and 6. Again, any number of fuel openings 38 may be provided, but it is preferable that four equally circumferentially spaced openings are provided as shown so that fuel may be supplied even when the heater is slightly tilted. Fuel is delivered to the openings 38 from a fuel manifold 39 having connections 40 extending to the fuel openings. A supply line 41 delivers fuel to the manifold 39.

Combustion air is supplied to the combustion chamber 37 from a combustion air chamber 42 that is annular in shape and in surrounding relation to the combustion chamber 37. The combustion air chamber 42 is defined by the combustion chamber wall 35 and a combustion air chamber wall- 43 arranged concentric to the wall 35. The combustion air chamber 42 is closed at its upper end by a wall 44. A plurality of rows of air openings 45, 46 and 47 are provided in the combustion chamber wall 35 to permit introduction of the air from the combustion air chamber 42 into the combustion chamber 37. The openings are arranged circumferentially around the cornbustion chamber wall 35 and spaced vertically from each other. A pilot ring 48 is arranged to extend inwardly from the combustion chamber wall 35 to hold the flame in the center of the combustion chamber. The upper end of the combustion chamber 37 is provided with a choke 49 that is merely defined by an inward extension of the bottom wall 18 of the main combustion chamber 13. Holes 50- are provided in the choke 49 in alignment or registry with holes 51 provided in the wall 19 to provide intercommunication between the pilot burner combustion chamber 37 and the main burner combustion chamber 13 as will be more fully explained hereinafter. While any number of holes 50 and 51 may be provided, it is preferred that only four holes circumferentially and equally spaced be provided as is shown.

Air-is supplied to the combustion air chambers from a plenum chamber 52 that surrounds the pilot burner and a part of the main burner and is somewhat annular in shape. The plenum chamber 52 is defined by a lower cyli-ndrical :casing section 53 of the outer casing 54 of the heater, abottom wall 55 of the heater, an upper annular wall 56 extending between the casing section 53 and the outer combustion air chamber wall 25, and the combustion chamber wall 25 and the outer combustion chamber wall 43. The bottom wall 55 is supported from the pilot burner 11 by a bracket and fastener arrangement 57, while the pilot burner 11 is secured and supported from the main burner by bracket and fastener means 58. The lower end of the casing wall 53 is suitably connected to the bottom wall 55, while the upper end is joined with the upper casing section wall 59 by suitable plate connecting means 60.

Air enters the plenum chamber 52 through a pair of oppositely disposed openings 61 in the outer wall 53 that have. a scoop 62 overlying same with a downwardly opening inlet 63 through which the air moves upwardly and into the opening 61. While only two air inlets are shown, it should be appreciated that any number may be employed. The air is thereby brought into the plenum chamber by a natural draft condition.

Air is supplied from the plenum chamber 52 to the combustion air chamber 42 by traveling below the lower end of the wall 43 and upwardly through an opening 64. The lower end of the combustion air chamber wall 25 is provided with an inwardly extending flange 65 that terminates short of the combustion air chamber wall 43 and thereby defines therewith an annular opening 66 through which air travels from the plenum chamber upwardly and into the outer combustion air chamber 15 for the main burner. Air is supplied to the inner combustion air chamber 14 through a plurality of connecting pipes 67 arranged in the main burner combustion chamber 13 and having inlets 67a in the bottom wall 18 of the main burner, and outlets 67b in the inner concentric wall 16.

The flue or combustion gases from the main burner move upwardly by the choke 40 and into a flue gas collection chamber 68, within which is supported the heating coil 12. The flue gas collection chamber is defined by an outer circular wall 69 that extends upwardly from the top wall 56 of the plenum chamber 52, and upper annular wall 71 extending from the wall 69 inwardly to a main burner stack pipe 71 that is arranged to extend outwardly of the heater and inwardly and down into a part of the heating coil 12. A cylindrical pilot stack wall 72 is arranged inwardly of the outer wall 69 to define the inner end of the collection chamber 68. An upwardly and outwardly extending deflector 73 is arranged along the pilot stack wall 72 to deflect the flue gases from the main combustion chamber outwardly toward the coils 12 and upwardly into the upper area of the flue gas collection chamher and then downwardly and around tthe lower edge of the wall 71 and out the main burner stack 74. Flue gases from the pilot burner 11 move upwardly past the choke 49, through the flue defined by the inner combustion air chamber wall 19, and through the pilot stack 75. The main burner stack 74 and the pilot stack 75 may be suitably connected to pipes to discharge the flue gases above a car having the heater.

The upper end of the casing 54 is provided with atop wall 76 extending from the casing wall section 59 inwardly to the main burner stack wall 71. Brackets 77 are secured to the top of the heater for suspending the heater on a car and preferably below the main body of the car for permanent usage.

Fuel is fed to the pilot and main burners from a fuel tank 78 and through a main shut-off valve '79 to a line 86. From the line 80, fuel is fed through a manually adjustable metering valve 81 and to the supply line 41 of the pilot burner 11. Also fuel is supplied from the line through a float valve 82 and a metering and control valve 83 to the supply line 34 of the main burner 10. The float valve 82 limits the amount of fuel in the combustion chamber 13 of the main burner 10, while the metering and control valve 83 serves to meter the fuel to the main burner and also to cycle the fuel supply thereto in response to a capillary and bulb arrangement 84 that is connected to the control system 85. The control system being the heating system either calls for heat or does not demand heat and thereby controls the valve 83. More specifically, a needle valve may be provided in the control valve 83 operated by a bellows that is connected to the capillary tube and bulb arrangement 84.

In operation, the heater is started by opening the main valve 79 of the fuel tank to allow fuel to be metered into the combustion chamber 37 of the pilot burner 11 and also into the combustion chamber 13 of the main burner 10. The float valve 82 limits the amount of fuel that can be supplied to the main burner combustion chamber and therefore precludes the supply of excess fuel thereto. An access tube 86 is'provided in the wall of the pilot burner 11, FIG. 2, and an access cover 87 with or without a sight glass closes the opening. Removal of the cover 87 permits the introduction of a lighted wick to light the pilot burner 11 after the fuel has been turned on. The combustion air that is supplied to the plenum is obtained through a natural draft arrangement. As the pilot burner begins to burn, it begins to preheat the lower part of the main burner until the fuel in the main burner becomes vaporized, and there-after ignited by the flames of the pilot burner combustion chamber that pass through the openings 50 and 51 into the main burner combustion chamber thereby igniting the fuel in the main burner. To further enhance the ignition of the fuel in the main burner, a tungsten wire 88 is mounted just inside of the openings 51 and across which the gases from the pilot burner pass to thereby cause it to glow. This tungsten wire is not necessary, but will serve to enhance ignition. The pilot burner operates all of the time at a low fire and thereby continues to preheat the combustion air in the pilot burner combustion chamber 42, as well as the combustion air in the main burner combustion air chamber 14. The main burner combustion chamber also preheats the air in both of its combustion air chambers to aid in the combustion of the fuel. Thus, the combustion air is preheated during operation of the burners to enhance combustion. Should the control system cease the need of heat, it would operate to turn off the dials 83 and turn off the main burner 10. Thereafter, when the heat is again needed the valve 83 would be cycled on so that the main burner can then re-ignite. It should be appreciated that the pilot burner is energized all of the time whenever it is needed. In order to determine whether the main burner is operating, a sight glass arrangement 89, FIG. 2, is provided which aligns with an opening 98 in the wall 69. As above mentioned, the flue gases from the main burner flow upwardly about the heating coils 10 in order to impart heat thereto and then out the main burner stack 74.

It will be understood that modifications and variations may be eflected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A heater comprising a main burner, a pilot burner and a heating coil, said main burner including an annular combustion chamber defined by upstanding inner and outer concentric walls and an annular bottom wall extending between said concentric walls, inner and outer annular combustion air chambers adjacent the inner and outer concentric walls defined respectively by said concentric walls and inner and outer circular combustion air chamber walls, openings in said concentric walls providing intercommunication between said air chambers and said combustion chamber, said pilot burner being arranged below said main burner and including a combustion chamber defined by an upstanding circular wall and a bottom wall across the lower end of the circular wall, a combustion air chamber encircling said pilot burner combustion chamber, openings in said circular wall providing intercommunication between said pilot burner combustion air chamber and combustion chamber, the inner main burner combustion air chamber wall defining a fine for said pilot burner wherein the upper open end of said pilot burner combustion chamber registers with said flue and also slightly underlies an inner part of the main burner bottom wall, openings at the lower end of the main burner combustion chamber providing intercommunication between said main burner combustion chamber and the pilot burner flue, means for feeding fuel to said burners, a

plenum chamber surrounding said pilot burner and the lower portion of said main burner and having an opening to the atmosphere, means intercom municating each of said combustion air chambers with said plenum chamber, a flue gas collection chamber above said main burner combustion chamber, and said heating coil in said collection chamber.

2. A heater as defined in claim 1, wherein means are provided in the main burner combustion chamber for delivering combustion air from said combustion air chambers toward the center of said combustion chamber.

3. A heater as defined in claim 2, wherein said means includes a plurality of tubular elements.

4. A heater as defined in claim 3, wherein said tubular elements extend inwardly and downwardly from said concentric walls in registry with openings therethrough.

5. A heater as defined in claim 1, wherein a circular perforated bafiie is mounted within said main burner cornbustion chamber in spaced relation between said concentric walls and concentric therewith, said bafiie being spaced upwardly from the bottom wall.

6. A heater as defined in claim 5, wherein said openings in said inner concentric wall are provided with tubular members to direct the combustion air into the area between said baffie and inner concentric Wall.

7. A heater as defined in claim 1, and a choke at the upper open end of said main burner combustion chamber.

8. A heater as defined in claim 1, wherein said fuel feeding means includes a plurality of fuel openings in the bottom walls of said combustion chambers.

9. A heater as defined in claim 8, wherein said fuel openings are circumferentially spaced and connected to a fuel manifold.

10. A heater as defined in claim 1, wherein a choke is provided at the upper open end of said pilot burner combustion chamber and openings are provided therethrough in alignment with the openings at the lower end of the main burner combustion chamber.

11. A heater as defined in claim 1, and an access opening in the circular wall of said pilot burner combustion chamber for facilitating lighting thereof.

12. A heater as defined in claim 1, wherein said fuel feeding means includes a metering valve for metering the fuel to said pilot burner, a metering and control valve for metering fuel to said main burner and cycling the burner, control means for operating said metering and control valve in response to the heat requirements of the heating system to which the heating coils are connected, and a float valve for limiting the amount of fuel in the main burner combustion chamber.

13. A heater as defined in claim 1, wherein means is provided in the combustion chamber in the path of the openings at the lower end thereof to facilitate ignition of said main burner.

14. A heater as defined in claim 13, wherein said means includes a tungsten wire.

References Cited UNITED STATES PATENTS 2,237,890 4/1941 Sabins 122-250 2,346,817 4/1944 Breese et al 158-91 X 3,017,925 1/1962 Breese et al 158-91 X FOREIGN PATENTS 708,429 4/ 1965 Canada. 1,192,148 4/1959 France.

CHARLES J. MYHRE, Primary Examiner, 

1. A HEATER COMPRISING A MAIN BURNER, A PILOT BURNER AND A HEATING COIL, SAID MAIN BURNER INCLUDING AN ANNULAR COMBUSTION CHAMBER DEFINED BY UPSTANDING INNER AND OUTER CONCENTRIC WALLS AND AN ANNULAR BOTTOM WALL EXTENDING BETWEEN SAID CONCENTRIC WALLS, INNER AND OUTER ANNULAR COMBUSTION AIR CHAMBERS ADJACENT THE INNER AND OUTER CONCENTRIC WALLS DEFINED RESPECTIVELY BY SAID CONCENTRIC WALLS AND INNER AND OUTER CIRCULAR COMBUSTION AIR CHAMBER WALLS, OPENINGS IN SAID CONCENTRIC WALLS PROVIDING INTERCOMMUNICATION BETWEEN SAID AIR CHAMBERS AND SAID COMBUSTION CHAMBER, SAID PILOT BURNER BEING ARRANGED BELOW SAID MAIN BURNER AND INCLUDING A COMBUSTION CHAMBER DEFINED BY AN UPSTANDING CIRCULAR WALL, A BOTTOM WALL ACROSS THE LOWER END OF THE CIRCULAR WALL, A COMBUSTION AIR CHAMBER ENCIRCLING SAID PILOT BURNER COMBUSTION CHAMBER, OPENINGS IN SAID CIRCULAR WALL PROVIDING INTERCOMMUNICATION BETWEEN SAID PILOT BURNER COMBUSTION AIR CHAMBER AND COMBUSTION CHAMBER, THE INNER MAIN BURNER COMBUSTION AIR CHAMBER WALL DEFINING A FLUE FOR SAID PILOT BURNER WHEREIN THE UPPER OPEN END OF SAID PILOT BURNER COMBUSTION CHAMBER REGISTERS WITH SAID FLUE AND ALSO SLIGHTLY UNDERLIES AN INNER PART OF THE MAIN BURNER BOTTOM WALL, OPENINGS AT THE LOWER END OF THE MAIN BURNER COMBUSTION CHAMBER PROVIDING INTERCOMMUNICATION BETWEEN SAID MAIN BURNER COMBUSTION CHAMBER AND THE PILOT BURNER FLUE, MEANS FOR FEEDING FUEL TO SAID BURNERS, A PLENUM CHAMBER SURROUNDING SAID PILOT BURNER AND THE 